Fan Motor and Electronic Device Comprising the Same

ABSTRACT

A fan motor and an electric device having the same are disposed. The fan motor and the electronic device having the same are provided with: a stator part including a coil and a stator yoke provided at a lower part of the coil; a rotor part including a magnet spaced apart from an upper surface of a stator yoke and a back yoke tightly provided on the upper surface of the magnet; a fan member including a rotating shaft which rotates to become a rotation center of the rotor part, and a plurality of impellers to which the magnet is fixedly coupled on inner circumferential surfaces of the impellers; a body part accommodating the stator part; and a cover part having an intake hole and an exhaust hole, and provided at an upper end part of the body part to accommodate the plurality of impellers.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No.10-2019-0005000, filed Jan. 15, 2019, the entire contents of which isincorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a fan motor that is applied to a kindof sensor module that detects temperature, humidity, and a dustturbidity state of indoor air of a vehicle, and further controls theoperation of an air cleaner of the vehicle. More particularly, thepresent invention relates to a fan motor and an electronic device havingthe same, the fan motor including: a stator part including a coil and astator yoke provided at a lower part of the coil; a rotor part includinga magnet spaced apart from an upper surface of the stator yoke and aback yoke tightly provided on the upper surface of the magnet; a fanmember including a rotating shaft which rotates to become a rotationcenter of the rotor part, and a plurality of impellers to which themagnet is fixedly coupled on inner circumferential surfaces of theimpellers; a body part accommodating the stator part; and a cover parthaving an intake hole and an exhaust hole, and provided at an upper endpart of the body part to accommodate the plurality of impellers, whereinthe stator yoke is seated in a groove part provided in the bottomsurface of the body part as a plate-shaped member, the groove part isprovided with a bearing housing for shaft-supporting a sleeve bearingelongated for rotationally supporting the rotating shaft, and thebearing housing is provided by protruding integrally with the body partin the central part where the groove part is provided, and thus the fanmotor not only prevents the axial deviation of the sleeve bearing, butalso solves the problem of an impact-loaded friction joint between thesleeve bearing and the rotating shaft, which is generated duringrotation, to increase operation life, and to facilitate easy qualitycontrol.

Description of the Related Art

The fan motor generally includes a motor that converts electrical energyinto mechanical energy, such as rotational force, and the fan motor mayclassified into an outer rotor type fan motor, an inner rotor type fanmotor, and a flat type fan motor, depending on whether a rotor isdisposed outside or inside a stator. Also, the fan motor has a structurein which a magnet and a coil are arranged in a vertical direction, andthe electromagnetic force flows sequentially to an edge part of the coilso that the magnet is rotated by the electromagnetic force.

The above mentioned fan motor removes a brush and a commutator from adirect current (DC) motor, is provided with a multipole magnet rotor,and employs a brushless motor that generates a rotating magnetic fieldby providing a driving coil at a position around the magnet rotor so asto drive the magnet rotor.

The brushless fan motor uses a sleeve bearing that is elongated torotationally support the rotating shaft in order to smoothly rotate therotating shaft of the motor. However, the fan motor using such a sleevebearing has the problems in that the sleeve bearing may be separated oran intermetallic friction joint may occur between the sleeve bearing andthe rotating shaft when the motor is driven.

Regarding the brushless fan motor as described above, Korean Patent No.10-1828065 and Korean Patent Application Publication No. 10-2018-0125132are proposed.

SUMMARY OF THE INVENTION

The present invention has been devised and developed to solve theproblems of the related art as described above, and an objective thereofis to provide a fan motor and an electronic device including the same,the fan motor including: a stator part including a coil and a statoryoke provided at a lower part of the coil; a rotor part including amagnet spaced apart from an upper surface of the stator yoke and a backyoke tightly provided on the upper surface of the magnet; a fan memberincluding a rotating shaft which rotates to become a rotation center ofthe rotor part, and a plurality of impellers to which the magnet isfixedly coupled on inner circumferential surfaces of the impellers; abody part accommodating the stator part; and a cover part having anintake hole and an exhaust hole, and provided at an upper end part ofthe body part to accommodate the plurality of impellers, wherein thestator yoke is seated in a groove part provided in the bottom surface ofthe body part as a plate-shaped member, the groove part is provided witha bearing housing for shaft-supporting the sleeve bearing elongated forrotationally supporting the rotating shaft, and the bearing housing isprovided by protruding integrally with the body part in the central partwhere the groove part is provided, and thus the present invention notonly prevents the axial deviation of a sleeve bearing, but also solvesthe problem of the impact-loaded friction joint between the sleevebearing and the rotating shaft, which is generated during rotation, toincrease operation life, and to facilitate easy quality control.

In order to achieve the objective of the present invention, there isprovided a fan motor including: a stator part including a coil and astator yoke provided at a lower part of the coil; a rotor part includinga magnet spaced apart from an upper surface of the stator yoke and aback yoke tightly provided on an upper surface of the magnet; a fanmember including a rotating shaft which rotates to become a rotationcenter of the rotor part, and a plurality of impellers to which themagnet is fixedly coupled on inner circumferential surfaces of theimpellers; a body part accommodating the stator part; and a cover parthaving an intake hole and an exhaust hole, and provided at an upper endpart of the body part to accommodate the plurality of impellers, whereinthe stator yoke is seated in a groove part provided in a bottom surfaceof the body part as a plate-shaped member, the groove part is providedwith a bearing housing for shaft-supporting a sleeve bearing elongatedfor rotationally supporting the rotating shaft, and the bearing housingis provided by protruding integrally with the body part in a centralpart where the groove part is provided.

In addition, in the present invention, a circuit board for driving thestator part may be disposed at a position between the stator yoke andthe magnet.

In addition, in the present invention, an end part of the bearinghousing may be provided with a bearing support part provided as an innercircumferential surface of the bearing housing to prevent the sleevebearing from separation.

In addition, in the present invention, the bearing support part mayprevent a bearing from separation by fixing the bearing through insertinjection molding, at least one caulking, or heat welding.

In addition, in the present invention, the fan motor may further includea separation prevention member provided at a position between thebearing support and the bearing.

In addition, in the present invention, the bearing housing may beprovided with a stopper part for matching centers of gravity of therotor part and the sleeve bearing.

In addition, in the present invention, the bearing housing may besimultaneously accommodated inside the stator part, inside the rotorpart, and inside the circuit board.

In addition, in the present invention, the stator yoke may be providedat a position in the groove part of the body part, and is fixed byinsert injection molding or heat welding.

In addition, in the present invention, the stator yoke may have apolygonal shape.

In addition, in the present invention, the coil of the stator part maybe a hollow coil, having a square shape.

In addition, in the present invention, an electric device includes a fanmotor including the above configuration.

The fan motor according to the present invention is effective in thatthe fan motor includes: a stator part including a coil and a stator yokeprovided at a lower part of the coil; the rotor part including a magnetspaced apart from an upper surface of a stator yoke and a back yoketightly provided on the upper surface of the magnet; a fan memberincluding a rotating shaft which rotates to become a rotation center ofthe rotor part, and a plurality of impellers to which the magnet isfixedly coupled on inner circumferential surfaces of the impellers; abody part accommodating the stator part; and a cover part having anintake hole and an exhaust hole, and provided at an upper end part ofthe body part to accommodate the plurality of impellers, wherein thestator yoke is seated in a groove part provided in the bottom surface ofthe body part as a plate-shaped member, the groove part is provided witha bearing housing for shaft-supporting the sleeve bearing elongated forrotationally supporting the rotating shaft, and the bearing housing isprovided by protruding integrally with the body part in the central partwhere the groove part is provided, and thus the fan motor not onlyprevents the axial deviation of a sleeve bearing, but also solves theproblem of the impact-loaded friction joint between the sleeve bearingand the rotating shaft, which is generated during rotation, to increaseoperation life, and to facilitate easy quality control.

In addition, the present invention reduces the lengths of the rotatingshaft and of the sleeve bearing to match the center of gravity with thefan member, and changes a production method of the bearing support partfrom the press to the injection molding. Accordingly, the presentinvention suppresses occurrence of the impact-loaded friction jointbetween the sleeve bearing and the rotating shaft, which is generatedwhen the motor rotates, thereby not only increasing the operation life,but also facilitating quality control.

In addition, the present invention provides the stator yoke in a polygonshape so that each vertex of the polygon of the stator yoke iscoincident with the center point of each of the N pole and the S pole ofthe multipole magnetized magnet. Therefore, the starting position of therotor part is determined, so it is possible to eliminate the magnet forsensing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a fan motor according to thepresent invention.

FIG. 2 is a perspective view of a state in which the fan motor is acompleted assembly according to the present invention.

FIG. 3 is a cross-sectional view of FIG. 2.

FIG. 4 is a detailed cross-sectional view around the fan member in thefan motor according to the present invention.

FIG. 5A is an exploded view of the fan member, and FIG. 5B is aperspective view of the fan member which is a completed assembly.

FIG. 6 is a coupled perspective view of the fan member and the body partin the present invention.

FIG. 7 is a detailed view of the body part.

FIG. 8 is a partial detail view of the body part.

FIG. 9A is a view showing a state without caulking on the upper part ofa sleeve bearing, and FIG. 9B is a view showing a state with caulking onthe upper part of the sleeve bearing.

FIG. 10 is a cross-sectional view of FIG. 9B.

FIG. 11 is a view showing another exemplary embodiment for preventingthe sleeve bearing from separation.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a fan motor that is applied to a kindof sensor module that detects temperature, humidity, and a dustturbidity state of indoor air of a vehicle, and further operates tocontrol driving of an air cleaner. Hereinafter, the fan motor will bedescribed in detail with reference to the accompanying drawings.

As shown in FIGS. 1 to 4, the fan motor according to the presentinvention includes: a cover part 10 having an intake hole 11 and anexhaust hole 12; a fan member 20 accommodated in a fan memberaccommodating part 13 provided inside the cover part 10 to include arotating shaft 32 that rotates to become the rotation center of a rotorpart, and provided with the plurality of impellers to which a magnet 33is fixedly coupled on the inner circumferential surfaces of theimpellers 22; a stator part including a coil 51 wound around a drivingcoil and a stator yoke 52 disposed at a position below the coil 51; therotor part including the magnet 33 spaced apart from an upper surface ofthe stator yoke 52, and a back yoke 31 tightly provided on the uppersurface of the magnet 33; a circuit board 40 generating driving powerand a control signal to the coil 51 to drive the stator part; and a bodypart 70 provided at a lower part of the cover part 10 to accommodate thestator part.

As shown in FIG. 2, the cover part 10 is provided with the intake hole11 and the exhaust hole 12 to help intake and exhaust air through aswirl chamber when the rotor part rotates.

As shown in FIGS. 5A and 5B, the fan member 20 includes: a fan memberbody 21 having an accommodating space 24 formed at a lower part thereof,in which the back yoke 31 and the magnet 33 are fixedly coupled to theaccommodating space 24; a plurality of impellers 22 integrally providedon an upper part of the fan member body 21; and a rotating shaftcoupling part 23 fixedly coupled to an upper end part of the rotatingshaft 32.

The stator part is composed of the coil 51 wound around the driving coiland the stator yoke 52 provided at a lower part of the coil 51 andothers. Without having a separate bobbin, the coil 51 practically has arectangular shape instead of a circular shape in order to use theelectromagnetic force generated from the edge part of the coil 51 whenpower is applied to a hollow coil. The hollow coil is provided on thelower part surface of a through part of the circuit board 40, and isdisposed between the stator yoke 52 and the circuit board 40.

The rotor part is composed of the magnet 33 spaced apart from an uppersurface of the stator yoke 52, and the back yoke 31 tightly provided onthe upper surface of the magnet 33. The rotor part has a structure inwhich the fan member 20 fixedly coupled to the upper end of the rotatingshaft 32 rotates in accordance with the rotating shaft rotating whendriving power is supplied to the stator part.

A cap-shaped bearing housing 60 capable of accommodating a sleevebearing 53 seated on the upper part of the body part 70 is integrallyprotruded from the body part 70 and, particularly from the central partof a groove part in which the stator yoke 52 is accommodated. The flatplate-shaped stator yoke 52 is mounted on the bottom of the bearinghousing 60 so as to be integrally provided at the bottom of the bodypart 70 by means of insert injection molding or heat welding.

As shown in FIGS. 8 to 10 with respect to the end part of the bearinghousing 60, an incised V-shape bearing support part is provided as aninner circumferential surface of the bearing housing in order to preventthe sleeve bearing 53 from separation. The bearing support part 62prevents the press-fitted sleeve bearing 53 from separation, by way offixing the sleeve bearing 53 through the insert injection molding,forming at least one caulking part 63 in which a part of the innercircumferential surface is cut inward, or fixing the upper end of thesleeve bearing 53 by the heat welding.

In addition, as shown in FIG. 11, in order to reduce the gap between theupper surface of the sleeve bearing 53 and the bearing support part 62,a separation prevention member 65 such as a washer may be furtherprovided between the bearing support part 62 and the sleeve bearing 53.In this case, the bearing support part 62 may be fixed by the insertinjection molding, caulking, or the heat welding to further prevent thesleeve bearing 53 from separation.

The centers of gravity of the rotor part and of the sleeve bearing 53may be matched by reducing the lengths of the rotating shaft 32 and ofthe sleeve bearing 53 so as to reduce shaking during the rotation of therotating shaft 32, thereby reducing the friction joint. In addition, thematerial of the bearing support part 62 may be changed to plasticinjection material so as to reduce the friction joint between therotating shaft 32 and the sleeve bearing 53. In order to match thecenters of gravity of the rotor part and the sleeve bearing 53 asdescribed above, a mounting height of the sleeve bearing 53 is needed tobe limited. Therefore, a stopper part 64 which limits the mountingheight of the sleeve bearing 53 is provided in the bearing housing 60.In other words, the present invention is devised such that the centersof gravity of the rotor part and the sleeve bearing 53 is checked in 3Dstereoscopic way, so that one end part out of two end parts inside thebearing housing plays a role as a stopper on the actual product. Byreducing the lengths of the rotating shaft 32 and of the sleeve bearing53 as described above to match the centers of gravity of the rotor partand the sleeve bearing 53, and by changing a production method of thebearing support part 62 to the injection molding, there is an effectthat the friction joint may be maximally reduced in comparison with theconventional structure supporting the rotating shaft 32 and the sleevebearing 53 long in the vertical direction. As an example, the stopperpart 64 is experimentally provided at a position of 1 mm±0.05 from thelower end part of the rotating shaft 32. In this case, the sleevebearing 53 practically has a length of 5 mm±0.1.

As shown in FIG. 6, the bearing housing 60 is simultaneouslyaccommodated inside the stator part, inside the rotor part, and insidethe circuit board 40.

In addition, the sleeve bearing 53 is mounted so that the centers ofgravity of the sleeve bearing 53 and the rotor part having the fanmember 20 coincide with each other. Accordingly, the sleeve bearing 53in the bearing housing 60 is provided to be accommodated in the fanmember 20.

The stator yoke 52, which is a plate-shape member, as shown in FIGS. 7and 8, is seated in the groove part 72 provided in the bottom surface 71of the body part 70. The groove part 72 is provided with the bearinghousing 60 for axially supporting the elongated sleeve bearing 53rotationally supporting the rotating shaft 32. The bearing housing 60protrudes integrally with the body part 70 at a central part in whichthe groove part 72 is provided. The stator yoke 53 is practicallyprovided in the groove part 72 of the body part 70 to be fixed by insertinjection molding or heat welding.

In addition, it is assumed that the stator yoke 52 has a polygonalshape. By providing the stator yoke 52 in the polygon shape, each vertexof the polygon of the stator yoke 52 coincides with the center point ofeach N pole and S pole of the multipole magnetized magnet 33.Consequently, the starting position of the rotor part is determined, soit is possible to eliminate the magnet for sensing.

Although the fan motor applied to the sensor module for the vehicle isdescribed above, the present invention is also applicable to theelectronic device to which the fan motor having the above structure isapplied.

In addition, as described above, the present invention has beendescribed with reference to the practical exemplary embodiments.However, those skilled in the art will appreciate that variousmodifications, additions and substitutions are possible, withoutdeparting from the scope and spirit of the present invention asdisclosed in the accompanying claims.

1. A fan motor comprising: a stator part comprising a coil and a statoryoke provided at a lower part of the coil; a rotor part comprising amagnet spaced apart from an upper surface of the stator yoke and a backyoke tightly provided on an upper surface of the magnet; a fan membercomprising a rotating shaft which rotates to become a rotation center ofthe rotor part, and a plurality of impellers to which the magnet isfixedly coupled on inner circumferential surfaces of the impellers; abody part accommodating the stator part; and a cover part having anintake hole and an exhaust hole, and provided at an upper end part ofthe body part to accommodate the plurality of impellers, wherein thestator yoke is seated in a groove part provided in a bottom surface ofthe body part as a plate-shaped member, the groove part is provided witha bearing housing for shaft-supporting a sleeve bearing elongated forrotationally supporting the rotating shaft, and the bearing housing isprovided by protruding integrally with the body part in a central partwhere the groove part is provided.
 2. The fan motor of claim 1, whereina circuit board for driving the stator part is disposed at a positionbetween the stator yoke and the magnet.
 3. The fan motor of claim 1,wherein an end part of the bearing housing is provided with a bearingsupport part provided as an inner circumferential surface of the bearinghousing to prevent the sleeve bearing from separation.
 4. The fan motorof claim 3, wherein the bearing support part prevents a bearing fromseparation by fixing the bearing through insert injection molding, atleast one caulking, or heat welding.
 5. The fan motor of claim 4,further comprising: a separation prevention member provided at aposition between the bearing support and the bearing.
 6. The fan motorof claim 1, wherein the bearing housing is provided with a stopper partfor matching centers of gravity of the rotor part and the sleevebearing.
 7. The fan motor of claim 2, wherein the bearing housing issimultaneously accommodated inside the stator part, inside the rotorpart, and inside the circuit board.
 8. The fan motor of claim 1, whereinthe stator yoke is provided at a position in the groove part of the bodypart, and is fixed by insert injection molding or heat welding.
 9. Thefan motor of claim 1, wherein the stator yoke has a polygonal shape. 10.The fan motor of claim 1, wherein the coil of the stator part is ahollow coil, having a square shape.
 11. (canceled)